13 Replies Latest reply on May 27, 2013 2:52 PM by Trevor.Dennis

    White light sources (and their quality)

    Level 7

      (continued from another thread)

       

      White LEDs are currently not a great way to illuminate your prints because they are not near full spectrum light sources.  Most "white" LEDs are currently blue or violet LEDs with a green or yellow phosphor added to look neutral - but they have very little light in other areas (especially red).  Some high end white LEDs are getting closer to full spectrum - but those are only recently available, and are not yet widespread.

       

      Cheap fluorescent lamps tend to have a few "spikes" of light and have some wavelenths almost entirely missing.  "Full Spectrum" Fluorescent lights are getting better, and cheaper - but are still not comparable in quality to tungsten or daylight.

       

      spectra1.pngspectra3.png

      Spectra4.png

      Spectra measured with X-Rite ColorMunki and Argyll CMS spotread utility. Multiple readings averaged, normalized and plotted in Microsoft Excel.

       

      [ updated Dec 16, 2012 to add white LED4, a recent Cree flashlight LED ]

      [ updated May 27, 2013 to add samples from 2 LED lightbulbs ]